(x3-3x+x+2):(x2-1)
rút gọn A,B,C
A=(3x+7)(2x+3)-(3x-5)(2x+11)
B=(x2-2)(x2+x-1)-x(x3+x2-3x-2)
C=x(x3+x2-3x-2)-(x2-2)(x2+x-1)
\(A=6x^2+23x+21-\left(6x^2+23x-55\right)=76\\ B=x^4+x^3-x^2-2x^2-2x+2-x^4-x^3+3x^2+2x\\ =2\\ C=x^4+x^3-3x^2-2x-\left(x^4+x^3-x^2-2x^2-2x+2\right)\\ =-2\)
Thực hiện phép chia:
a) ( x 3 - 3x - 2) : (x - 2);
b) ( x 3 + 6 x 2 + 8x - 3): ( x 2 + 3x -1);
c) (2 x 4 – 7 x 3 + 9 x 2 - 7x + 2): (2 x 2 - 5x + 2).
a) x 2 + 2x + 1. b) x + 3. c) x 2 – x + 1.
Bài 1 Rút gọn biểu thức
a, [(3x - 2)(x + 1) - (2x + 5)(x2 - 1)] : (x + 1)
b, (2x + 1)2 - 2(2x + 1)(3 - x) + (3 - x)2
c, (x - 1)2 - (x + 1) (x2 - x + 1) - (3x + 1)(1 - 3x)
d, (x2 + 1)(x - 3) - (x - 3)(x2 + 3x + 9)
e, (3x +2)2 + (3x - 2)2 - 2(3x + 2)(3x - 2) + x
Bài 2 Phân tích các đa thức sau thành nhân tử
1, 3(x + 4) - x2 - 4x
2, x2 - xy + x - y
3, 4x2 -25 + (2x + 7)(5 - 2x)
4, x2 + 4x - y2 + 4
5, x3 - x2 - x + 1
6, x3 + x2y - 4x - 4y
7, x3 - 3x2 + 1 - 3x
8, 2x2 + 3x - 5
9, x2 - 7xy + 10y2
10, x3 - 2x2 + x - xy2
a)A=3x(2/3x2-3x4)+(3x2)(x3-1)+(-2+9).x2-12
b)B=x(2x3+x+2)-2x2(x2+1)+x2-2x+1
c)C=x.(2x+1)-x2(x+2)+x3-x+3
a, \(A=2x^3-9x^5+3x^5-3x^2+7x^2-12=-6x^5+2x^3+4x^2-12\)
b, \(B=2x^4+x^2+2x-2x^3-2x^2+x^2-2x+1=2x^4-2x^3+1\)
c, \(C=2x^2+x-x^3-2x^2+x^3-x+3=3\)
Thực hiện phép tính:
1)(x3-8):(x-2)
2)(x3-1):(x2+x+1)
3)(x3+3x2+3x+1):(x2+2x+1)
4)(25x2-4y2):(5x-2y)
1) \(\left(x^3-8\right):\left(x-2\right)=\left[\left(x-2\right)\left(x^2+2x+4\right)\right]:\left(x-2\right)=x^2+2x+4\)
2) \(\left(x^3-1\right):\left(x^2+x+1\right)=\left[\left(x-1\right)\left(x^2+x+1\right)\right]:\left(x^2+x+1\right)=x-1\)
3) \(\left(x^3+3x^2+3x+1\right):\left(x^2+2x+1\right)=\left(x+1\right)^3:\left(x+1\right)^2=x+1\)
4) \(\left(25x^2-4y^2\right):\left(5x-2y\right)=\left[\left(5x-2y\right)\left(5x+2y\right)\right]:\left(5x-2y\right)=5x+2y\)
B= (x2-2)(x2+x-1)-x(x3+x2-3x-2)
\(\left(x^2-2\right)\left(x^2+x-1\right)-x\left(x^3+x^2-3x-2\right)\)
\(=x^4+x^3-x^2-2x^2-2x+1-x^4-x^3+3x^2+2x\)
\(=x^4-x^4+x^3-x^3-x^2-2x^2+3x^2-2x+2x+1\)
\(=1\)
Tính.
a, (x3-2x2-10x-7):(x2-7-3x)
b, (x3+4x2+8x+5):(x+1)
c, (x3-x2-13x-14):(x2-3x-7)
d, (x3+5x2+5x):(x+5)
a: \(=\dfrac{x^3-3x^2-7x+x^2-3x-7}{x^2-3x-7}=x+1\)
b:\(=\dfrac{x^3+x^2+3x^2+3x+5x+5}{x+1}=x^2+3x+5\)
c:\(=\dfrac{x^3-3x^2-7x+2x^2-6x-14}{x^2-3x-7}=x+2\)
d: \(=\dfrac{x^2\left(x+5\right)+5x+25-25}{x+5}=x^2+5-\dfrac{25}{x+5}\)
a/2x5y-6x3y2
b/14x2y-xy2+28x2y2
c/x2+4x+4
d/9x2+6x+1
e/2x-1-x2
j/-x3+9x2-27x+27
g/(x+y)2-9x2
h/x2+xy+x+y
i/x2-4+xy-2y
k/x3-4x2+4x
k/x2-3x+2
l/x2-3x+2
m/x2-5x+6
n/x2-3x-4
c: \(x^2+4x+4=\left(x+2\right)^2\)
d: \(9x^2+6x+1=\left(3x+1\right)^2\)
Chứng tỏ rằng mỗi biểu thức sau không phụ thuộc vào giá trị của biến x :
A=(x2-2)(x2+x-1)-x(x3+x2-3x-2)
B=2(2x+x2)-x2(x+2)+(x3-4x+3).
a) x2(x-2)2-(x-2)^2 - x2 +1 b) x3-4x2+8x-8
c)1+6x-6x2-x3
d)x3-y3-3x2+3x-1
e)(x+y+z)^3-x3-y3-z3
ai biet de bai thi giup ban ay nha